Relay with contact springs

ABSTRACT

The relay has a base body, an electromagnet system having a coil, core and armature, as well as a contact arrangement having at least one stationary contact spring and at least one moving contact spring. The contact springs are each designed as planar sheet-metal parts and are anchored in the base body approximately in the same plane, without any permanent bending. In order to make contact, they are provided with an overlap by means of L-shaped end sections; in addition, prestressing of the stationary contact springs is produced by in each case one stop on the base body.

BACKGROUND OF THE INVENTION

The invention relates to a relay having

a base body,

an electromagnet system which is connected to the base body and has acoil, a core and an armature, and

a contact arrangement having at least one stationary contact spring andat least one moving contact spring which are anchored at leastapproximately in a common plane alongside one another in the base bodyand whose contact-making regions overlap one another by virtue of theL-shaped design of at least one contact spring, in which case it ispossible for the armature to operate the moving contact spring via aslide which can move approximately at right angles to the longitudinalextent of said moving contact spring.

DE-AS 20 39 939 discloses a contact unit for such a relay. There,contact springs and mating contact supports are in each case anchored ina common plane in a dielectric body, lateral overlapping of thecontact-making ends being achieved by means of bending. This involves aseries of accurate bending processes during the production of thecontact elements, the process of mounting in the dielectric body, whichpreferably involves embedding there, also being dependent on complexguidance and alignment.

DE 26 27 168 discloses a moving contact spring being split into twolimbs, one limb being designed as a contact limb and the other as arestoring limb. Although use of this measure in a relay of the typementioned above is possible, it would, however, involve a more complexdesign of the individual parts.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide a relay of the typementioned initially, which is equipped with contact springs of as simplea form as possible, in which case these contact springs are intended tobe capable of being produced and assembled as easily as possible, inorder that the relay, overall, can be produced in a particularlycost-effective manner.

According to the invention, this aim is achieved in that all the contactsprings are designed as planar leaf springs without any permanentbending, and in that the stationary contact spring, resting on a stop onthe base body, is prestressed by elastic deflection from its clamping-inplane.

Thus, in the case of the relay according to the invention, the contactarrangement (which, in the simplest case, is designed as a break contactor as a make contact) has only contact springs which are stamped from aplanar metal sheet, are not prebent in any way and overlap one anotherby virtue of the L-shaped design of at least one spring end.Prestressing of the stationary contact spring in the rest state and acontact gap (if this is a make contact) are produced by a stop on thebase body, on which stop the relevant contact spring rests only byvirtue of insertion into the base body, and experiences correspondingdeflection. For its part, the moving contact spring normally rests onthe slide, by means of which (in the rest state and depending on thetype of contact) it can likewise be deflected at this stage to a greateror lesser extent from its plane. In any case, the contact springs can beproduced very cost-effectively and easily, since the respective springcharacteristic is not achieved by permanent bends on the contact springsbut by the geometry of the base body with the stop, at least for thestationary contact spring. If there are a number of contact springs, anumber of different stops can also, of course, be provided in order toachieve correspondingly different prestresses.

A particularly simple design of the relay is obtained if a coil formerhaving two coil flanges is used as the base body, the contact springsbeing anchored approximately parallel to the coil axis in a first coilflange, and the stop which produces the prestressing being provided onthe second coil flange. Production becomes particularly cost-effectiveespecially if the stationary contact spring and the moving contactspring are of identical design, being inserted into the base body in thecommon plane, with mirror-image symmetry with respect to one another.

In a preferred refinement of the relay according to the invention themagnet has a T-shaped system whose longitudinal limb extends axiallythrough the coil former, a U-shaped armature being arranged on that sideof the coil former which faces away from the contact springs, and thetransverse web of the U-shaped armature being mounted in the region ofthe first coil flange on the free end of the core longitudinal limb, andthe free ends of the longitudinal arms of the armature operating theslide.

A particularly simple design of the relay, with few parts, is alsoobtained if the moving contact spring exerts a restoring force on thearmature, via the slide. In this case, a preferred refinementfurthermore provides that via a fulcrum in the central region of itslongitudinal limbs, the armature is forced by the restoring force of thecontact spring into its mounting on the core end. This fulcrum can beproduced without any additional parts by the armature having lateralshoulders which are integrally formed on both sides and rest on an inneredge of the housing cap.

An advantageous further refinement provides that, on a stationarycontact spring, an integrally formed restoring spring arm, which isdecoupled from the contact spring itself, acts on the slide and, viathis slide, prestresses the armature into its rest position.

Owing to the fact that the restoring spring arm is integrally formed ona stationary contact spring which is any case supported on the basebody, the dimensions and spring characteristics of the moving contactspring can be designed just to produce the respective contact pressure.This also allows a break contact or a changeover contact to be producedin a simple manner. In this case, no further individual parts arerequired apart from the additional break spring; the moving contactspring and the make contact spring can be used as in the case of themake-contact relay, without any design change. The restoring spring armis preferably integrally formed on the stationary break contact spring,as a result of which no interference occurs with the moving contactspring, and this provides the solution with the simplest design.

The invention will be explained in more detail in the following textusing exemplary embodiments and with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded illustration of a make-contact relay designedaccording to the invention,

FIGS. 2 and 3 show two perspective views of a completely assembled relayaccording to FIG. 1—without a cap,

FIG. 4 shows a section through the coil axis of the completely assembledrelay from FIG. 1,

FIG. 5 shows an exploded illustration of a changeover-contact relaydesigned according to the invention,

FIG. 6 shows the relay from FIG. 5 in the half-assembled state, butwithout a moving contact spring and without a make-contact spring, and

FIG. 7 shows a perspective view of a completely assembled relay—withouta cap.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The relay illustrated in the drawing comprises a coil former 1, a core 2which is T-shaped or approximately M-shaped, a U-shaped armature 3, aslide 4 in the form of a card, a stationary contact spring 5, a movingcontact spring 6, a cap 7 as well as two coil connecting pins 8 whichare anchored in the coil former.

The coil former 1 has an axial through-opening 11 as well as a firstflange 12 and a second flange 13, between which a winding 10 is fitted.At the end, an attachment 14 for armature mounting is integrally formedon the coil flange 12, and merges into a base plate 15. Limiting orsafety pins 16 for the armature are also integrally formed on theattachment 14, and plug-in slots 17 are additionally formed in thisattachment, through which connecting elements 51 and 61, respectively,of the contact springs 5 and 6 can be passed through the base plate 15vertically outwards. Furthermore, a stop tab 18 for the stationarycontact spring 5 is integrally formed on the second coil flange 13.

The T-shaped core 2 has a longitudinal limb 21 which is inserted intothe through-opening 11 in the coil former, as well as two transverselimbs 22, to each of whose ends side arms 23 are fitted, parallel to thelongitudinal limb 21. The U-shaped armature 3 comprises two longitudinalarms 31 and one transverse web 32, the latter of which is mounted on thefree end section 24 of the core 2 and is then located in a recessbetween the first coil flange 12 and the base plate 15. The armature isprotected against lateral movements by the two safety pins 16 on thebase attachment 14, which engage in corresponding recesses 33 in thearmature, without this impeding its switching movement. The free ends ofthe longitudinal arms 31 are broadened to form hook-shaped pole ends 34,which engage around the second coil flange 13, and form two parallel airgaps, when the relay is open, with the transverse limbs 22 and theirside arms 23 of the core.

The stationary contact spring 5 and the moving contact spring 6 areanchored by their connecting elements 51 and 61, respectively, in theplug-in slots 17 in the base attachment 14, and these connectingelements 51 and 61 are integrally formed or are attached in a knownmanner. In the present example, the two contact springs 5 and 6 are ofidentical design, and are provided with contacts 52 and 62,respectively.

The mutual overlap in order to make contact is produced by an L-shapedend portions 53 and 63 (see FIGS. 2 and 3) at their moving,contact-making ends.

The contact springs 5 and 6 are just cut out of flat sheet metal withoutany bend, and are inserted into the coil former. The mutual offsetbetween their contact-making ends is obtained simply from the geometryof the coil former and of the slide 4. This slide is located between thecoil flange 13 and the transverse limbs 22 of the core. It has a recessor opening 41 through which the core longitudinal limb 21 is passed.Once the parts have been joined together, the end section 53 (which hasan L-shape) of the stationary contact springs 5 rests on the stop tab 18of the coil former 1, and is thus given its prestressing in the restposition. On the other side of the contact, the end section 63 (which anL-shape) of the moving contact spring 6 rests on the slide 4. When theslide 4 is operated by the armature, the end section 63 is moved in thedirection of the end section 53 of the stationary contact spring 5, andlifts the latter off its stop on the tab 18. This is how the contactforce is produced.

After assembly of the individual parts described, the cap 7 is fittedover the relay. This cap 7 forms a closed housing with the base plate15. As can be seen from FIG. 4, in the region of its top, the cap 7 hasa ventilation hole 71, which opens into an attachment 72 which projectsinwards. The latter attachment forms an additional guide for the slide4. As can also be seen from FIG. 4, the armature 3 is prestressed, viathe slide 4, in its rest position by the restoring force of themake-contact spring 6. In the process, lateral shoulders 35 of thearmature strike against ribs 72 on the cap, by which means a fulcrum 73is formed for the armature. Via this fulcrum 73, the lever effect causesthe mounted end and the transverse web 32 of the armature to be forcedinto the mounting and against the end section 24 of the core. Thisresults in reproducible flux transfer relationships in the armaturemounting, and correspondingly low pull-in excitation.

The changeover relay illustrated in FIGS. 5 to 7 comprises a coil former1, a T-shaped, or approximately T-shaped, core 2, a U-shaped armature, aslide 4 in the form of a card, a stationary make-contact spring 5, amoving contact spring 6, a stationary break-contact spring 9, a cap 7 aswell as two coil connecting pins 8 which are anchored in the coilformer. While the individual parts are of identical or similar design tothose in the preceding example of the make-contact relay, they have thesame reference symbols and are not described in any further detailspecifically.

The break-contact spring 9 is mounted in a plug-in slot 19 in the baseplate 15. While the sheet-metal planes of the two contact springs 5 and6 are mounted in a common plane in the plug-in slots 17, the sheet-metalplane of the contact spring 9 is arranged to be slightly offset withrespect to the former in the plug-in slot 19, but parallel to it. Allthe contact springs are provided with stop lugs 55 as well as 65 and 95,respectively, which are integrally formed at the sides and by means ofwhich they rest on the top of the respective plug-in slots 17 and 19,while bending lugs 56 and 66 as well as 96, respectively, on theunderneath in each case can be deformed for protection.

In this case as well, the contact springs 5 and 6 are simply cut from aflat metal sheet without any bending, and are inserted into the coilformer. The stationary break-contact spring 9 is likewise cut out of aflat metal sheet and is inserted into the coil former, namely into theplug-in slot 19. This spring 9 has a contact 92, which is opposite themoving contact 62. In addition, a restoring spring arm 94 is integrallyformed in the same plane on the break-contact spring 9 and is decoupledfrom the actual break-contact spring, beyond whose free end it projectsand acts as a restoring spring.

Once the parts have been joined together, the end section 53 (which hasan L-shape) of the stationary make-contact spring 5 rests on the stoptab 18 on the coil former 1 and is thus given its rest prestressing. Onthe other side of the contact, the end section 63 (which has an L-shape)of the moving contact spring 6 rests on an operating tab 43 on the slide4. The slide is also guided via a guide tab 42 in an aperture 64 in thecontact spring 6. Furthermore, the slide has an additional stop tab 44,on which the restoring spring arm 94 rests and, via the slide,prestresses the armature into its rest position.

In the rest state, the slide and (through it) the armature are thus heldby the spring arm 94 in their rest position, while the contact 62 makesa closed circuit with the contact 92. When the slide 4 is operated bythe armature, the end section 63 of the moving contact spring 6 is movedin the direction of the end section 63 of the make-contact spring; atthe same time, the contact 62 is lifted off the contact 92, and is madeto touch the contact 52. At the same time, the end section 53 is alsolifted off the stop on the tab 18, so that the contact force of the makecontact is built up. Once the excitation is switched off, the slide ismoved by the restoring force of the spring arm 94 into the originalposition, as a result of which the make contact is opened, and the breakcontact is closed.

What is claimed is:
 1. A relay comprising: a base body; anelectromagnetic system which is connected to the base body, saidelectromagnetic system having a coil with a central axis, a core on saidcentral axis and an armature; and a contact arrangement having astationary contact spring and a moving contact spring, each contactspring being a planar leaf spring with a connecting element and acontact-making region, the contact-making region of at least one contactspring having an L-shaped design, the connecting element of each of saidsprings being anchored in a common plane alongside one another in thebase body with contact-making regions overlapping one another, so thatthe armature can operate the moving contact spring via a slide which canmove at right angles to a longitudinal extent of said moving contactspring, the improvements comprising said stationary contact springresting on a stop on the base body and having the contact-making regionbeing prestressed by elastic deflection from the common plane by saidstop and said common plane extending parallel to the central axis.
 2. Arelay according to claim 1 , wherein said base body is a coil formerhaving first and second coil flanges, the contact springs are anchoredin the first coil flange, and the stop which produces the prestressingfor the stationary contact spring is integrally formed on the secondcoil flange.
 3. A relay according to claim 1, wherein the stationarycontact spring and the moving contact spring are of identical shape andare inserted into the base body in a plane with mirror-image symmetrywith respect to one another.
 4. A relay according to claim 1, whereinthe stationary contact spring has an integrally formed restoring springarm, which is decoupled from the stationary contact spring, and acts onthe slide to prestress the armature into a rest position.
 5. A relayaccording to claim 4, which has a moving contact spring, a stationarymake contact spring and a stationary break contact spring anchored inthe base body, and the restoring spring arm is integrally formed on thebreak contact spring and acts on an attachment on the slide next to themoving contact spring.
 6. A relay comprising: a base body; anelectromagnetic system which is connected to the base body, saidelectromagnetic system having a coil with a central axis, a core on saidaxis and an armature; and a contact arrangement having a stationarycontact spring and a moving contact spring, each contact spring being aplanar leaf spring with a connecting element and a contact-makingregion, the contact-making region of at least one contact spring havingan L-shaped design, the connecting element of each spring being anchoredin a common plane alongside one another in the base body withcontact-making regions overlapping one another, so that the armature canoperate the moving contact spring via a slide which can move at rightangles to the longitudinal extent of said moving contact spring, theimprovements comprising said stationary contact spring resting on a stopon the base body and having the contact-making region being prestressedby elastic deflection from the common plane by said stop, said base bodybeing a coil former having first and second coil flanges, the contactsprings being anchored parallel to the coil axis in the first coilflange, and the stop which produces the prestressing for the stationarycontact spring being integrally formed on the second coil flange, thecore being a T-shaped core having a longitudinal limb with transverselimbs extending therefrom, said longitudinal limb extending axiallythrough the coil former, the armature being a U-shaped armature withlongitudinal arms extending from a transverse portion arranged on a sideof the coil former which faces away from the contact springs and beingmounted by a transverse portion in a region of the first coil flange ona free end of the longitudinal limb of the core, and the longitudinalarms of the U-shaped armature having free ends to operate the slide. 7.A relay according to claim 6, wherein the slide is guided between thesecond coil flange and the transverse limbs of the core.
 8. A relayaccording to claim 6, wherein the moving contact spring exerts arestoring force on the armature, via the slide.
 9. A relay comprising: abase body having a pair of planar slots arranged in a common plane; anelectromagnetic system which is connected to the base body, saidelectromagnetic system having a coil with a central axis, a core on saidcentral axis and an armature; and a contact arrangement having astationary contact spring and a moving contact spring, each contactspring being a planar leaf spring with a connecting element and acontact-making region, the contact-making region of at least one contactspring having an L-shaped design, the connecting elements of the springsbeing anchored in the pair of slots of the base body with contact-makingregions overlapping one another, so that the armature can operate themoving contact spring via a slide which can move at right angles to alongitudinal extent of said moving contact spring, said stationarycontact spring resting on a stop on the base body and having thecontact-making region being prestressed by elastic deflection from thecommon plane by said stop and said common plane extending parallel tothe central axis.
 10. A relay according to claim 9, wherein said basebody is a coil former having first and second coil flanges, the contactsprings are anchored in the first coil flange, and the stop whichproduces the prestressing for the stationary contact spring isintegrally formed on the second coil flange.
 11. A relay according toclaim 9, wherein the stationary contact spring and the moving contactspring are of identical shape and are inserted into the slots of thebase body in a plane with mirror-image symmetry with respect to oneanother.
 12. A relay according to claim 9, wherein the stationarycontact spring has an integrally formed restoring spring arm, which isdecoupled from the stationary contact spring, and acts on the slide toprestress the armature into a rest position.
 13. A relay according toclaim 12, which has a moving contact spring, a stationary make contactspring and a stationary break contact spring anchored in the base body,and the restoring spring arm is integrally formed on the break contactspring and acts on an attachment on the slide next to the moving contactspring.
 14. A relay according to claim 9, wherein the base body is acoil former having first and second coil flanges, said pair of slotsbeing in the first coil flange, the stop is integrally formed on thesecond coil flange, the core is a T-shaped core having a longitudinallimb with transverse limbs extending therefrom, said longitudinal limbextends axially through the coil former, the armature is a U-shapedarmature with longitudinal arms extending from a transverse portionarranged on a side of the coil former which faces away from the contactsprings and is mounted by a transverse portion in a region of the firstcoil flange on a free end of the longitudinal limb of the core, and thelongitudinal arms of the U-shaped armature have free ends to operate theslide.
 15. A relay according to claim 14, wherein the slide is guidedbetween the second coil flange and the transverse limbs of the core. 16.A relay according to claim 14, wherein the moving contact spring exertsa restoring force on the armature, via the slide.